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powerpc/885: set SDCR to 0x40

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The MPC885 reference manual says that SDCR shall have value 0x40, but
most exemples set SDCR to 0x1
With 0x1 in SDCR, we observe TX underruns on SCC when using it in
QMC mode.
According the NXP technical support, this is a copy/paste error from
MPC860 reference manual, 0x40 being the only value supported
by the MPC885 HW.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
This commit is contained in:
Christophe Leroy 2016-02-04 11:07:48 +01:00 • committed by Scott Wood
parent b278268b63
commit 501ea76687
1 changed files with 4 additions and 1 deletions
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5
arch/powerpc/sysdev/cpm1.c
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@ -228,7 +228,10 @@ void __init cpm_reset(void)
* Bit 25, FAM can also be set to use FEC aggressive mode (860T).
*/
siu_conf = immr_map(im_siu_conf);
out_be32(&siu_conf->sc_sdcr, 1);
if ((mfspr(SPRN_IMMR) & 0xffff) == 0x0900) /* MPC885 */
out_be32(&siu_conf->sc_sdcr, 0x40);
else
out_be32(&siu_conf->sc_sdcr, 1);
immr_unmap(siu_conf);
cpm_muram_init();